Auto merge of #6794 - camsteffen:needless-borrowed-ref, r=flip1995

Improve needless_borrowed_ref docs

changelog: none

I think "borrowed ref" is a confusing description for this lint. Destructuring a reference is the opposite of borrowing. So I updated the wording throughout the docs. Unfortunately this nit applies to the name of the lint itself, but I won't bother changing that. One motivation for these changes is to clarify the difference between this lint and `needless_borrow` (they are actually quite different). Let me know if I need to clarify anything or if you disagree with any changes.